Use the MCP server

pacs-mcp is a standalone MCP server. It exposes three tools over FHIR R4 REST and IRIS vector search. It does not call the KomPACS API.

Patient data

The tools return report text. Connect a client to real patient data only if the client sends text to an EU Data Zone LLM. Use test data with any other client.

Prerequisites

• Python 3.12 or later and uv.
• A FHIR R4 server. For search_reports: IRIS with the vec.ReportSentence table.
• The pacs-mcp package source.

Configure

Variable	Required	Use
PACS_MCP_DATA	yes	synthetic (test data) or eu-data-zone (real data, EU Data Zone client only). The server refuses to start without it.
FHIR_BASE	yes	FHIR R4 base URL
FHIR_USER, FHIR_PASSWORD	no	Basic auth for the FHIR server
IRIS_HOST, IRIS_PORT, IRIS_NAMESPACE, IRIS_USER, IRIS_PASSWORD	for search_reports	IRIS SQL connection. Use a least-privilege user.

Run

PACS_MCP_DATA=synthetic FHIR_BASE=http://localhost:52773/fhir/r4 uv run pacs-mcp

The transport is stdio. The client starts the server as a child process.

Connect a client

Example client config, for a synthetic FHIR server only:

{
  "mcpServers": {
    "pacs": {
      "command": "uv",
      "args": ["run", "--directory", "mcp", "pacs-mcp"],
      "env": {
        "FHIR_BASE": "http://localhost:52773/fhir/r4",
        "PACS_MCP_DATA": "synthetic"
      }
    }
  }
}

Inspect the tools with the MCP Inspector:

PACS_MCP_DATA=synthetic FHIR_BASE=http://localhost:52773/fhir/r4 \
  npx @modelcontextprotocol/inspector uv run pacs-mcp

Ask a question

A typical agent loop:

1. The agent lists the tools and sends them with the question to the LLM.
2. The LLM asks for a tool call, for example get_case_summary.
3. The agent calls the tool and returns the result.
4. After up to 6 rounds, the LLM answers with FHIR references.

The LLM never calls MCP directly. The agent is the MCP client.

Tools: MCP tools reference.